It seems, therefore, that the incest taboo was and is aimed at one thing in particular: to preserve the family unit and its proper functioning.

Incest is more than a mere manifestation of a given personality disorder or a paraphilia (incest is considered by many to be a subtype of pedophilia). It harks back to the very nature of the family. It is closely entangled with its functions and with its contribution to the development of the individual within it.

The family is an efficient venue for the transmission of accumulated property as well as information - both horizontally (among family members) and vertically (down the generations). The process of socialization largely relies on these familial mechanisms, making the family the most important agent of socialization by far.

The family is a mechanism for the allocation of genetic and material wealth. Worldly goods are passed on from one generation to the next through succession, inheritance and residence. Genetic material is handed down through the sexual act. It is the mandate of the family to increase both by accumulating property and by marrying outside the family (exogamy).

Clearly, incest prevents both. It preserves a limited genetic pool and makes an increase of material possessions through intermarriage all but impossible.

The family's roles are not merely materialistic, though.

One of the main businesses of the family is to teach to its members self control, self regulation and healthy adaptation. Family members share space and resources and siblings share the mother's emotions and attention. Similarly, the family educates its young members to master their drives and to postpone the self-gratification which attaches to acting upon them.

The incest taboo conditions children to control their erotic drive by abstaining from ingratiating themselves with members of the opposite sex within the same family. There could be little question that incest constitutes a lack of control and impedes the proper separation of impulse (or stimulus) from action.

Additionally, incest probably interferes with the defensive aspects of the family's existence. It is through the family that aggression is legitimately channeled, expressed and externalized. By imposing discipline and hierarchy on its members, the family is transformed into a cohesive and efficient war machine. It absorbs economic resources, social status and members of other families. It forms alliances and fights other clans over scarce goods, tangible and intangible.

This efficacy is undermined by incest. It is virtually impossible to maintain discipline and hierarchy in an incestuous family where some members assume sexual roles not normally theirs. Sex is an expression of power - emotional and physical. The members of the family involved in incest surrender power and assume it out of the regular flow patterns that have made the family the formidable apparatus that it is.

These new power politics weaken the family, both internally and externally. Internally, emotive reactions (such as the jealousy of other family members) and clashing authorities and responsibilities are likely to undo the delicate unit. Externally, the family is vulnerable to ostracism and more official forms of intervention and dismantling.

Finally, the family is an identity endowment mechanism. It bestows identity upon its members. Internally, the members of the family derive meaning from their position in the family tree and its "organization chart" (which conform to societal expectations and norms). Externally, through exogamy, by incorporating "strangers", the family absorbs other identities and thus enhances social solidarity (Claude Levy-Strauss) at the expense of the solidarity of the nuclear, original family.

Exogamy, as often noted, allows for the creation of extended alliances. The "identity creep" of the family is in total opposition to incest. The latter increases the solidarity and cohesiveness of the incestuous family - but at the expense of its ability to digest and absorb other identities of other family units. Incest, in other words, adversely affects social cohesion and solidarity.

Lastly, as aforementioned, incest interferes with well-established and rigid patterns of inheritance and property allocation. Such disruption is likely to have led in primitive societies to disputes and conflicts - including armed clashes and deaths. To prevent such recurrent and costly bloodshed was one of the intentions of the incest taboo.

The more primitive the society, the more strict and elaborate the set of incest prohibitions and the fiercer the reactions of society to violations. It appears that the less violent the dispute settlement methods and mechanisms in a given culture - the more lenient the attitude to incest.

The incest taboo is, therefore, a cultural trait. Protective of the efficient mechanism of the family, society sought to minimize disruption to its activities and to the clear flows of authority, responsibilities, material wealth and information horizontally and vertically.

Incest threatened to unravel this magnificent creation - the family. Alarmed by the possible consequences (internal and external feuds, a rise in the level of aggression and violence) - society introduced the taboo. It came replete with physical and emotional sanctions: stigmatization, revulsion and horror, imprisonment, the demolition of the errant and socially mutant family cell.

As long as societies revolve around the relegation of power, its sharing, its acquisition and dispensation - there will always exist an incest taboo. But in a different societal and cultural setting, it is conceivable not to have such a taboo. We can easily imagine a society where incest is extolled, taught, and practiced - and out-breeding is regarded with horror and revulsion.